Producing radioactive Thallium products for pharmaceutical use, like other hazardous or valuable materials, is a fairly complex process with many steps and requirements. One requirement during production is that pH samples of the product have to be tested very often. A typical day may require four to ten pH tests. Each test requires a two-point calibration of the probe, along with a wash and dry of the probe before and between taking these calibration measurements. A two-point calibration requires that the pH probe be cleaned and dried, followed by a dip in a first buffer fluid, setting the probe electronics to the pH level of the first buffer; a second cleaning and drying, followed by a dip in a second buffer, and setting the probe electronics to reflect the second buffer level. As a result, a typical day of thallium production may require many buffer dips, cleans, and dries per day. Furthermore, performing these tests manually, with paper testing, dipping of the probe into fluids such as buffer 4, buffer 7, and water for injection, and subsequent towel drying the of the probe is very manually intensive work, time consuming, and also results in shutting down the process as well as risking contamination or exposure to the human operator.
Additionally, testing the pH is a destructive test and waste of the sampled fluid because it requires fluid to be removed from the fluid container and tested for its pH level. Should the pH level be too high or too low, a pH additive is added to the sample. Testing is repeated until the sample fluid reads as being at the desired pH level. All of the fluid tested is lost or wasted since it will not be added back into original sample container but disposed of as waste during the subsequent cleaning of the probe. Even though the amounts of fluid may seem to be small, for particularly hazardous or valuable fluids, such losses can be quite costly due to the loss of product or even just the cost of handing and disposing of a radioactive or biologically sensitive material.
In order to eliminate the loss or exposure of the hazardous fluid, there is a need a for a closed-loop conduit system incorporating an in-line probe. While probes for manually dipping into a sample well are available, no probes are provided in an assembly for use in a closed-loop system. In order to calibrate or clean the probe, the probe must be manually transferred from the sample well to a cleaning or calibration station. Valuable or hazardous product on the probe may be lost or exposed to the atmosphere, endangering the surrounding environment, the handler, or the product itself.
There is therefore a need for a probe which may be provided integrally to a fluid handling or dispense system. There is also a need for a fluid sampling system with an in-line probe. The in-line probe should be able to be calibrated and cleaned without requiring disassembly of the probe from the system. Additionally, there is a need for a fluid sampling system which allows the monitoring and adjustment of the pH level of the fluid conducted within.